Lightweight Flow Control

These were adapted from HerkForth.

| 0=;  |  n- | exit word if TOS = 0                                   | | 0<>; |  n- | exit word if TOS <> 0                                  | | <;   | nn- | exit word if NOS < TOS                                 | | >;   | nn- | exit word if NOS > TOS                                 | | <>;  | nn- | exit word if NOS <> TOS                                | | if;  |  f- | exit word if TOS is TRUE                               | | ?;   |  f- | exit word if TOS is TRUE. Leave Flag on stack if TRUE. |

~~~:0=;  n:zero? [ as{ 'popopodr i 'drdrre.. i }as ] if ; :0<>; n:zero? [ as{ 'popopodr i 'drdrre.. i }as ] -if ; :<;   lt?     [ as{ 'popopodr i 'drdrre.. i }as ] if ; :>;   gt?     [ as{ 'popopodr i 'drdrre.. i }as ] if ; :<>;  -eq?    [ as{ 'popopodr i 'drdrre.. i }as ] if ; :if;          [ as{ 'popopodr i 'drdrre.. i }as ] if ; :?;   dup     [ as{ 'popopodr i 'drdrre.. i }as ] if drop ; ~~~

Tests

```:test (n-) n:even? if; 'Odd! s:put nl ;   #1 test #2 test ```

```nl '----------------- s:put nl :test (n-) n:even? ?; 'Odd! s:put nl ; #1 test dump-stack reset nl #2 test dump-stack reset nl ```